Trimming attachment for sewing-machines



(No Model.)

J. BIGELOW. TRIMMING ATTACHMENT FOR SEWING MAGHINES. No. 313,802.Patented Mar. 10, 1885 lUNirnn Sra rns PATENT tries.

JOHN BIGELOW, or PHILADELPHIA, PENNSYLVANIA.

TRllVllVllNG ATTACHMENT FORSEWING ll/IACHINES SPECIFICATION forming partof Letters Patent No. 313,802, dated March 10, 1885.

(No model.)

To all whom it may concern.-

Be it known that 1, JOHN BIGELOW, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements inTrimming Attachments for Sewing-Machines; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same, reference being had to the accompanying drawings,and to letters or figures of reference marked thereon, which form a partof this specification.

This invention relates to the construction of a shear trimming deviceadapted to sewing-machines, and more particularly to the position andmethod of securing the stationary blade.

The construction of the upper blade is practically the same as shown inmy application filed June 5, 1879.

Figure l is an end View showing upper blade, rock-shaft, lower orstationary blade, and its holding device. Fig. 2 is a plan View. Fig. 3is a rear view showing the position of the stationary blade. Fig. 4 is adetail View of the crank. Fig. 5 is a diagram showing position ofstationary blade.

The cutting-edges of the blades A and B, Fig. 1, are placedin the usualrelation to each other to make a shear or draw out. The upper blade, B,is attached to the anglepiece 13, Fig. 1, which in turn is secured tothe rock-shaft (1, having bearings at D and G, Fig. 2. The shaft 0 isshouldered at 0'. It is surrounded by a coil-spring, F, one end of whichpresses against the shoulder G and 0 the other end against the loosebearing G.

A crank, E, surrounds the shaft 0 at E", and can be set in any positionon the same by means of the clamp-screw E, Fig. 4. The crank E receivesavibrating movement at E' from any suitable moving part of the machine.The lower or stationary blade, A, is a long plate having one of its endsA cut off at an acute angle and sharpened to a shearedge.

In order to save the necessity of hollow grinding the blade is placed ina laterally and longitudinally inclined position, as shown in Figs. 3and 5. This position tends to make its cutting-edge incline away fromthe cutting-edge of the blade B. To avoid this, the plate or blade A isset at an acute angle to the cutting-line, as shown at A in. Fig. 5, K Kbeing the cutting'line, A A" the cuttingedge of the blade A, and ,A A Kan enlarged view ofthe acute angle to which I have referred. The shaft0, carrying the upper blade, is raised sufficiently high in its bearings to allow the blade A to pass under it, as shown in Fig. 1. Theblade A can be held in position in the manner shown in my application ofJune 5, 1879, or by the block H and screw H shown in the drawings.

The operation of the mechanism is that of most shearing devices. Theblade B is vibrated by its connection with the rocking shaft 0, and itscutting-edge V is kept against the cutting-edge A of the lower blade, A,by the action of the spring F pressing at C on the shaft 0. V

This device has its stationary hearing attached to the workplate ofasewing-machine at F, and its bearing D adjustably attached through theslotted openings shown in Fig. 2. The cutting-edges are just behind thesewingneedle, and can be set in any desired relation thereto by the setof the bearing D.

I claim 1. A stationary seam-trimmer blade having its body set at anacute angle to a vertical plane, within which said blades cuttingedgeand the vibrating blade are located, in combination with a vibratingblade and the work-plate and stitch-forming mechanism of asewing-machine, substantially as described.

2. In combination with the stitch-forming mechanism of a sewing machine,a shear trimming device consisting of a vibrating blade and a stationaryblade, the latter arranged to be adjusted forward in a direction at anacute angle with a vertical plane, within which said blades cutting-edgeand the cuttingedge of the vibrating blade are located, substantially asdescribed.

8. In combination with the stitch-forming mechanism of a sewing-machine,a trimming device consisting of a vibrating blade, and a stationaryblade which is a long plate having neath said rock-shaft at an acuteangle to a vertical plane, within which said blades cutting-edge and thecutting-edge of the vibrating blade are located, substantially asdescribed.

In testimony whereof I affix my signature in presence of two witnesses.

\ JOHN BIGELOW.

Witnesses: G. W. BALLOOH, L. DEnNE.

